We’re So Outta Here

The wide variety of migrations from, through, and even to Montana each winter. By Dave Carty

This story is featured in Montana Outdoors November-December 2013 issue

It’s winter, and across Montana animals are either sticking it out like the rest of us, or they’ve headed south. Most species staying here are mammals, reptiles, and amphibians, such as bears, rattle­snakes, and salamanders. Crows, ravens, and magpies tough it out, too, as do all of our upland game birds. But most birds leave. They may love our summers, but once they sense cold weather coming, they pack their bags and catch the next flight out of town.

Freeze babiesSome birds skedaddle out of the Treasure State before summer has barely begun. “The long-billed curlews that breed in Montana sometimes migrate all the way back to Mexico as early as late June, which is amazing,” says Steve Hoffman, executive director of Montana Audubon. Western tanagers and Bullock’s orioles also exit early, departing Montana in late July and early August.

Mourning doves are notorious for skipping town just before Montana’s dove hunting season opens September 1. Many a dove hunter has stood in a stubble field on Labor Day weekend staring at empty skies.

“There’s still plenty of food here in Montana in early September, but doves migrate out anyway,” says Jim Hansen, FWP’s Central Flyway migratory bird coordinator. Even our balmy September nights can be too chilly for the heat-loving mourners. “They leave because of a combination of decreasing day length and decreasing temperature,” Hansen says. “If the temperatures stay warm, especially at night, they’ll stick around longer, maybe even until the 10th of September or so. But some time around then is when you start getting nighttime lows into the 40s, and that’s when doves start heading south.”

Just coming throughMany birds fly through Montana each fall from northern summering grounds to warmer locales south of us. Count among those snow geese, Canada geese, and other waterfowl, as well as neotropical warblers like the common yellowthroat and American redstart. Among the last of the passers-through are tundra swans, scaup, and mallards pushed south as late as early December when the lakes and even rivers of Canada’s Prairie Provinces freeze over.

Birds of prey from Canada and Alaska use Montana’s geology like an aerial interstate on their way south. One well-known migrating raptor concentration is just north of Bozeman in the Bridger Range. Viewers have spotted 16 different species during the
migration peak in early October, including some of the largest concentrations of
golden eagles in North America.

Hoffman says the raptors ride thermals created along the east side of the Rocky Mountain Front south from Alberta. Once in central Montana, the get funneled along the Bridgers. “That range has a single ridgeline instead of multiple ones that would spread out the updrafts,” he says.

Assisted by the almost perfect soaring conditions above the Bridgers, many of the eagles could conceivably shoot south
another 100 to 200 miles by the end of the day, says Hoffman. That pace would put them at their wintering grounds in Texas and northern Mexico in just a few short weeks.

Welcome to MontanaAs cold and windy as Montana gets in January and February, some birds actually fly here from even worse weather to spend the winter. Goldeneyes, mallards, and Canada geese from our neighbor to the north are just a few examples. Common redpolls and Bohemian waxwings prefer the Treasure State to the northern Canadian provinces where they breed. Every few years, in what’s known as an “irruption,” snowy owls from the Arctic migrate to “mild” Montana and other northern states in the Lower 48, likely due to
declines in Arctic lemming populations.

Montana’s most commonly seen winter arrivals are rough-legged hawks. To these birds, which nest on the face of cliffs over­looking Arctic tundra, our state probably looks like Fort Lauderdale. In the Arctic, they live on lemmings and voles, so switching to mice and voles in Montana isn’t much of an adjustment. And true to their nature, when the weather warms just a little, they’re anxious to head north again. They begin migrating back to the Arctic as early as March and April.

New studies show that sage-grouse from Alberta and Saskatchewan migrate into
Montana from the Hi-Line south to the
Missouri River Breaks. So do pronghorn. Thousands of antelope migrate from southern Canada across northern Montana, some even crossing frozen Fort Peck Reservoir. Like the sage-grouse, the pronghorn are drawn by the relatively easy grazing on windswept and snow-free prairies along the Milk River or Missouri River Breaks. “I used to keep track of herds along the Milk River northwest of Glasgow, and in the hills I’d see groups of from 50 up to several hundred,” says FWP wildlife biologist Kelvin Johnson. “We had one herd that eventually got up to about 700 animals.”

Tiny travelers
Amazingly, some insects also head south before the snow flies. Most Montana insects overwinter here as eggs, larvae, nymphs, or pupae, or hibernate as adults in tree cavities (like the mourning cloak moth) or barns and attics (such as wasps and ladybugs). But some adult dragonflies and beetles fly south, likely to “hedge their bets” by reproducing in different locales. Recent studies by British scientists show that several moth species fly half a mile or more into the sky to catch fast tailwinds that propel them to warmer locations.

Aside from tiny moths flying 1,500 miles south to Mexico, perhaps the most heroic migration from Montana is that of the
calliope hummingbird, the world’s smallest migrating bird.
Along with Montana’s rufous, broad-tailed, and black- chinned hummingbirds, the caliope summers in the state’s central and western regions. Now retired, Ned and Gigi Batchelder of Hamilton spend their free time banding and studying hummers. “We’ve caught and banded birds in Montana and then caught them later in Wyoming. When we figured out the mileage, it came out to 20 or 30 miles a day,” Ned says. “Migrating hummingbirds don’t hitch rides on the backs of geese, which is an old myth that just will not die. But how they do migrate is still pretty fascinating. A lot of people don’t even know that they end up in Mexico, and that they may migrate five years in a row during their lives.” The Batchelders catch the hummingbirds in a cage trap baited with a feeder. During the migration peak, they capture and band up to 100 birds each day.

Not always southMost birds migrating south from Montana end up along the Texas coast or in Mexico or Central or South America. Not all, though. Some snow geese passing through Freezeout Lake spend the winter at Tule Lake near Sacramento, California. Harlequin ducks, which nest in and around Glacier National Park, winter along the Pacific Coast in British Columbia. “Some bald eagles that summer in Montana return to Arizona in September to get ready to breed there in late fall and early winter,” says Montana Audubon’s Hoffman.

The longest winter migration from Montana is that of the
upland sandpiper, which flies more than 6,000 miles to winter in Argentinian pampas, or prairies.

The award for shortest winter migration out of Montana goes to several dozen sage-grouse that nest in southwestern Montana near Lima Peak. Each fall the birds fly roughly 40 to 60 miles south to their relatively snow-free wintering grounds around Mud Lake in southeastern Idaho. “I’ve observed them flying overhead more than 500 feet in the air,” says Craig Fager, FWP wildlife biologist in Dillon. “I looked up and thought, ‘What on earth is that?’ I’ve also found them up on the Continental Divide near Monida, and flushed them into Idaho. They can actually set their wings in Montana and coast for miles on that glide.”

The sage-grouse raise their chicks in Idaho. When the young birds are big enough to fly, they head to Montana in search of the succulent plants and grasshoppers that
evidently are more plentiful—and maybe also tastier—than the plants and ’hoppers just a few miles south in Idaho.

That’s the thing about migration. Whether it’s just across the border into another state or across the globe to another hemisphere, migrators are looking elsewhere for something they can’t find where they happen to be. Many fly, walk, or glide to locales they may have never seen before and from which they may not return. But their offspring will, and their offspring’s offspring, in an unending cycle of coming and going that countless numbers of their kind have followed for eons.

Dave Carty is a regular contributor to Montana Outdoors.

In 1930 Montana’s schoolchildren voted for the western meadowlark as the bird that best represented the state. The following year, the Montana Legislature made it official. Then in 1998 several lawmakers proposed to replace the meadowlark with the magpie. The legislators argued—unsuccessfully—that the songbird flees to Mexico each fall when temperatures begin to drop, while the magpie stays in Montana year round and is more deserving of the state bird honor.